Lean Manufacturing Techniques - Quick Changeover
Producing and delivering make-to-order products to exacting customer quality, price and delivery requirements can only be achieved successfully if manufacturing is efficiently geared up for wide variety, small batch production. With wide variety, small batch production, the impact of set-up times becomes a significant factor in overall production performance.
Achieving a quick changeover of tooling, checking and assembly jigs and fixtures etc, is therefore essential. When methods are in place to accommodate quick changeover, set-ups can be achieved much more frequently. Wide variety, small batch production will then deliver the required advantages of flexibility, quicker delivery, better quality and higher productivity.
Single Minute Exchange of Die
Single Minute Exchange of Die (SMED) is a method of reducing changeover time to 9 minutes or less.
For best results, SMED techniques should only be targeted at bottleneck areas within the process.
- Firstly ensure that 5S action has been taken beforehand to improve working area layout and tool accessibility and eliminate wasteful changeover movements.
- Next, identify and separate internal set-up activities (carried out whilst machine is stopped) from external set-up activities (carried out whilst the machine is running).
- Identify whether any of the internal set up operations could be performed as external operations i.e. outside the cycle time of the machine. e.g. moulds normally preheated on the machine itself could be preheated in advance in a small off-line oven.
- Finally, re-design tooling or changeover equipment fixtures for quick release and insertion/removal, incorporating caddies or tool carriers for off-line set up.
- If changeover procedures are not already standardised, a procedures or operations manual should be created and then developed to incorporate subsequent improvements in the changeover methods used.
